// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: BUSL-1.1

package command

import (
	"encoding/json"
	"fmt"
	"regexp"
	"strconv"
	"strings"
	"time"

	"github.com/hashicorp/nomad/api"
	"github.com/hashicorp/nomad/helper/pointer"
	"github.com/posener/complete"
)

var (
	// enforceIndexRegex is a regular expression which extracts the enforcement error
	enforceIndexRegex = regexp.MustCompile(`\((Enforcing job modify index.*)\)`)
)

type JobRunCommand struct {
	Meta
	JobGetter
}

func (c *JobRunCommand) Help() string {
	helpText := `
Usage: nomad job run [options] <path>
Alias: nomad run

  Starts running a new job or updates an existing job using
  the specification located at <path>. This is the main command
  used to interact with Nomad.

  If the supplied path is "-", the jobfile is read from stdin. Otherwise
  it is read from the file at the supplied path or downloaded and
  read from URL specified.

  Upon successful job submission, this command will immediately
  enter an interactive monitor. This is useful to watch Nomad's
  internals make scheduling decisions and place the submitted work
  onto nodes. The monitor will end once job placement is done. It
  is safe to exit the monitor early using ctrl+c.

  On successful job submission and scheduling, exit code 0 will be
  returned. If there are job placement issues encountered
  (unsatisfiable constraints, resource exhaustion, etc), then the
  exit code will be 2. Any other errors, including client connection
  issues or internal errors, are indicated by exit code 1.

  If the job has specified the region, the -region flag and NOMAD_REGION
  environment variable are overridden and the job's region is used.

  When ACLs are enabled, this command requires a token with the 'submit-job'
  capability for the job's namespace. Jobs that mount CSI volumes require a
  token with the 'csi-mount-volume' capability for the volume's
  namespace. Jobs that mount host volumes require a token with the
  'host_volume' capability for that volume.

General Options:

  ` + generalOptionsUsage(usageOptsDefault) + `

Run Options:

  -check-index
    If set, the job is only registered or updated if the passed
    job modify index matches the server side version. If a check-index value of
    zero is passed, the job is only registered if it does not yet exist. If a
    non-zero value is passed, it ensures that the job is being updated from a
    known state. The use of this flag is most common in conjunction with plan
    command.

  -detach
    Return immediately instead of entering monitor mode. After job submission,
    the evaluation ID will be printed to the screen, which can be used to
    examine the evaluation using the eval-status command.

  -eval-priority
    Override the priority of the evaluations produced as a result of this job
    submission. By default, this is set to the priority of the job.

  -json
    Parses the job file as JSON. If the outer object has a Job field, such as
    from "nomad job inspect" or "nomad run -output", the value of the field is
    used as the job.

  -hcl2-strict
    Whether an error should be produced from the HCL2 parser where a variable
    has been supplied which is not defined within the root variables. Defaults
    to true.

  -output
    Output the JSON that would be submitted to the HTTP API without submitting
    the job.

  -ui
    Open the job page in the browser.

  -policy-override
    Sets the flag to force override any soft mandatory Sentinel policies.

  -preserve-counts
    If set, the existing task group counts will be preserved when updating a job.

  -consul-namespace
    (Enterprise only) If set, any services in the job will be registered into
    the specified Consul namespace. Any template block reading from Consul KV
    will be scoped to the specified Consul namespace. If Consul ACLs are
    enabled and the "consul" block "allow_unauthenticated" is disabled in the
    Nomad server configuration, then a Consul token must be supplied with
    appropriate service and KV Consul ACL policy permissions.

  -vault-namespace
    If set, the passed Vault namespace is stored in the job before sending to the
    Nomad servers.

  -var 'key=value'
    Variable for template, can be used multiple times.

  -var-file=path
    Path to HCL2 file containing user variables.

  -verbose
    Display full information.
`
	return strings.TrimSpace(helpText)
}

func (c *JobRunCommand) Synopsis() string {
	return "Run a new job or update an existing job"
}

func (c *JobRunCommand) AutocompleteFlags() complete.Flags {
	return mergeAutocompleteFlags(c.Meta.AutocompleteFlags(FlagSetClient),
		complete.Flags{
			"-check-index":      complete.PredictNothing,
			"-detach":           complete.PredictNothing,
			"-verbose":          complete.PredictNothing,
			"-consul-namespace": complete.PredictAnything,
			"-vault-namespace":  complete.PredictAnything,
			"-output":           complete.PredictNothing,
			"-policy-override":  complete.PredictNothing,
			"-preserve-counts":  complete.PredictNothing,
			"-json":             complete.PredictNothing,
			"-hcl2-strict":      complete.PredictNothing,
			"-var":              complete.PredictAnything,
			"-var-file":         complete.PredictFiles("*.var"),
			"-eval-priority":    complete.PredictNothing,
			"-ui":               complete.PredictNothing,
		})
}

func (c *JobRunCommand) AutocompleteArgs() complete.Predictor {
	return complete.PredictOr(
		complete.PredictFiles("*.nomad"),
		complete.PredictFiles("*.hcl"),
		complete.PredictFiles("*.json"),
	)
}

func (c *JobRunCommand) Name() string { return "job run" }

func (c *JobRunCommand) Run(args []string) int {
	var detach, verbose, output, override, preserveCounts, openURL bool
	var checkIndexStr, consulNamespace, vaultNamespace string
	var evalPriority int

	flagSet := c.Meta.FlagSet(c.Name(), FlagSetClient)
	flagSet.Usage = func() { c.Ui.Output(c.Help()) }
	flagSet.BoolVar(&detach, "detach", false, "")
	flagSet.BoolVar(&verbose, "verbose", false, "")
	flagSet.BoolVar(&output, "output", false, "")
	flagSet.BoolVar(&override, "policy-override", false, "")
	flagSet.BoolVar(&preserveCounts, "preserve-counts", false, "")
	flagSet.BoolVar(&c.JobGetter.JSON, "json", false, "")
	flagSet.BoolVar(&c.JobGetter.Strict, "hcl2-strict", true, "")
	flagSet.StringVar(&checkIndexStr, "check-index", "", "")
	flagSet.StringVar(&consulNamespace, "consul-namespace", "", "")
	flagSet.StringVar(&vaultNamespace, "vault-namespace", "", "")
	flagSet.Var(&c.JobGetter.Vars, "var", "")
	flagSet.Var(&c.JobGetter.VarFiles, "var-file", "")
	flagSet.IntVar(&evalPriority, "eval-priority", 0, "")
	flagSet.BoolVar(&openURL, "ui", false, "")

	if err := flagSet.Parse(args); err != nil {
		return 1
	}

	// Truncate the id unless full length is requested
	length := shortId
	if verbose {
		length = fullId
	}

	// Check that we got exactly one argument
	args = flagSet.Args()
	if len(args) != 1 {
		c.Ui.Error("This command takes one argument: <path>")
		c.Ui.Error(commandErrorText(c))
		return 1
	}

	if err := c.JobGetter.Validate(); err != nil {
		c.Ui.Error(fmt.Sprintf("Invalid job options: %s", err))
		return 1
	}

	// Get Job struct from Jobfile
	sub, job, err := c.JobGetter.Get(args[0])
	if err != nil {
		c.Ui.Error(fmt.Sprintf("Error getting job struct: %s", err))
		return 1
	}

	// Get the HTTP client
	client, err := c.Meta.Client()
	if err != nil {
		c.Ui.Error(fmt.Sprintf("Error initializing client: %s", err))
		return 1
	}

	// Force the region to be that of the job.
	if r := job.Region; r != nil {
		client.SetRegion(*r)
	}

	// Force the namespace to be that of the job.
	if n := job.Namespace; n != nil {
		client.SetNamespace(*n)
	}

	// Check if the job is periodic or is a parameterized job
	periodic := job.IsPeriodic()
	paramjob := job.IsParameterized()
	multiregion := job.IsMultiregion()

	if consulNamespace != "" {
		job.ConsulNamespace = pointer.Of(consulNamespace)
	}

	if vaultNamespace != "" {
		job.VaultNamespace = pointer.Of(vaultNamespace)
	}

	if output {
		req := struct {
			Job *api.Job
		}{
			Job: job,
		}
		buf, err := json.MarshalIndent(req, "", "    ")
		if err != nil {
			c.Ui.Error(fmt.Sprintf("Error converting job: %s", err))
			return 1
		}

		c.Ui.Output(string(buf))

		return 0
	}

	// Parse the check-index
	checkIndex, enforce, err := parseCheckIndex(checkIndexStr)
	if err != nil {
		c.Ui.Error(fmt.Sprintf("Error parsing check-index value %q: %v", checkIndexStr, err))
		return 1
	}

	// Set the register options
	opts := &api.RegisterOptions{
		PolicyOverride: override,
		PreserveCounts: preserveCounts,
		EvalPriority:   evalPriority,
		Submission:     sub,
	}
	if enforce {
		opts.EnforceIndex = true
		opts.ModifyIndex = checkIndex
	}

	// Submit the job
	resp, _, err := client.Jobs().RegisterOpts(job, opts, nil)
	if err != nil {
		if strings.Contains(err.Error(), api.RegisterEnforceIndexErrPrefix) {
			// Format the error specially if the error is due to index
			// enforcement
			matches := enforceIndexRegex.FindStringSubmatch(err.Error())
			if len(matches) == 2 {
				c.Ui.Error(matches[1]) // The matched group
				c.Ui.Error("Job not updated")
				return 1
			}
		}

		c.Ui.Error(fmt.Sprintf("Error submitting job: %s", err))
		return 1
	}

	// Print any warnings if there are any
	if resp.Warnings != "" {
		c.Ui.Output(
			c.Colorize().Color(fmt.Sprintf("[bold][yellow]Job Warnings:\n%s[reset]\n", resp.Warnings)))
	}

	evalID := resp.EvalID

	jobNamespace := c.Meta.namespace
	if jobNamespace == "" {
		jobNamespace = "default"
	}

	// Check if we should enter monitor mode
	if detach || periodic || paramjob || multiregion {
		c.Ui.Output("Job registration successful")
		if periodic && !paramjob {
			loc, err := job.Periodic.GetLocation()
			if err == nil {
				now := time.Now().In(loc)
				next, err := job.Periodic.Next(now)
				if err != nil {
					c.Ui.Error(fmt.Sprintf("Error determining next launch time: %v", err))
				} else {
					c.Ui.Output(fmt.Sprintf("Approximate next launch time: %s (%s from now)",
						formatTime(next), formatTimeDifference(now, next, time.Second)))
				}
			}
		} else if !paramjob {
			c.Ui.Output("Evaluation ID: " + evalID)
		}

		hint, _ := c.Meta.showUIPath(UIHintContext{
			Command: "job run",
			PathParams: map[string]string{
				"jobID":     *job.ID,
				"namespace": jobNamespace,
			},
			OpenURL: openURL,
		})
		if hint != "" {
			c.Ui.Warn(hint)
		}

		return 0
	}

	// Detach was not specified, so start monitoring
	hint, _ := c.Meta.showUIPath(UIHintContext{
		Command: "job run",
		PathParams: map[string]string{
			"jobID":     *job.ID,
			"namespace": jobNamespace,
		},
		OpenURL: openURL,
	})
	if hint != "" {
		c.Ui.Warn(hint)
		// Because this is before monitor, newline so we don't scrunch
		c.Ui.Warn("")
	}

	mon := newMonitor(c.Ui, client, length)
	return mon.monitor(evalID)

}

// parseCheckIndex parses the check-index flag and returns the index, whether it
// was set and potentially an error during parsing.
func parseCheckIndex(input string) (uint64, bool, error) {
	if input == "" {
		return 0, false, nil
	}

	u, err := strconv.ParseUint(input, 10, 64)
	return u, true, err
}
